MT Prep - Friction is a Force

The topic of our text today is F.R.I.C.T.I.O.N --

___

Remember with a pencil - take notes!

Comments on the Finches + GAME at the end of the post

"A fair result can be obtained only by fully stating and balancing the facts and arguments on both sides of each question. "

Charles Darwin

 So let's think about our experiment in class yesterday--modelling natural selection with spoons and scissors and macaroni and toothpicks and a bunch of other stuff.  What did it mean, and also what did it not mean?
Here is a shortened version of an article from this site, Truth in Science, which you or your parents might appreciate for a fuller discussion.

Darwin's Finches

Galapagos finches showing different beak shapes

On the Galapagos Islands in the Pacific Ocean, close to the equator, there are a variety of different finches, which vary in the shape and size of their beaks. It appears that the  finches colonised the Islands from mainland South America, and then diverged in form. The distance between the islands meant that the finches on different islands could not interbreed, so the populations on the different island tended to become distinct. Different populations also became specialised for different food sources, birds with thin, sharp beaks eating insects and birds with large, sturdy beaks eating nuts.

Darwin collected some of these finches when he visited the Galapagos Islands, and it is often stated that the finches were key to the development of his theory of evolution. They are used as evidence for his theory in many textbooks.

Were the Finches important to Darwin in formulating his theory?

When he was on the Galapagos Islands, Darwin did not notice that different islands had different finches. Neither did he realise that the finches were closely related despite their differences in beak shape. He did not match different beak shapes to different diets. Even after his return to London, Darwin's biographers note that he "remained confused by the Galapagos finches...unaware of the importance of their different beaks...He had no sense of a single, closely related group becoming specialized and adapted to different environmental niches." (p. 209, Darwin - A. Desmond and J. Moore).

So all Darwin did was speculate that the different finches had descended from a common ancestor and had changed to be able to do different things. He was never sure that the different species were from different islands. He certainly never came up with the detailed theory for how the finches diversified which the BBC suggests. ...


What do the Finches demonstrate about evolution?
Though the finches were not important in the work of Charles Darwin, they do tell us something about evolution. In particular, over the past few decades, two scientists have done an excellent long term study on the finches on one of the Galapagos Islands. This is accurately described by the textbook Advanced Biology. (Jones, M., and G. Jones. 1997. Cambridge University Press) The authors recount how from 1977 to 1982 there was a drought on one of the Galapagos Islands, and due to natural selection the average finch beak size became larger…

However, this proved not to be the end of the story. If it continued in this way, the average beak size of G. fortis would continue to get larger and larger. But this has not happened (p. 153)

This cumulative change does not occur for two reasons. (1) There are disadvantages to having a large beak, especially when a bird is young. This can outweigh [no pun intended!] the advantages. (2) The selection pressure on the island fluctuates. In 1982 the drought stopped and there was selection for birds with small beaks.

It can therefore be argued that the study shows natural limits to evolutionary change. Variation in a species is a good thing, as it gives them the ability to cope with environmental change, but variation does have limits.

Many textbooks do not go into such detail, and simply describe the finches as a good example of a range of species evolving from a common ancestor.

The Galapagos finches afford an excellent example of adaptive radiation. It is assumed by evolutionists that a stock of ancestral finches reached the islands from the mainland and then, in the absence of much competition, evolved to fill many of the empty ecological niches occupied on the mainland by species absent from the islands.” (p. 725) Advanced Biology. Roberts, M., M. Reiss, and G. Monger. 2000. Nelson

Conclusion
The Galapagos finches were not as important to Darwin as is often claimed, but they are a good example of micro-evolution. They show us that finches can vary in their morphology [shape], and that natural selection has a role in this.

This study does not give evidence for macro-evolution, and does not prove that natural selection and random mutation could produce the living world as we know it from simple single-celled ancestors.

******************************************************
So here is a fun interactive that sums up what natural selection is--NOT NECESSARY to AGREE or to draw a conclusion--simply to understand the idea.
Who Wants To Live a Million Years? Game click here
Read, and then play the game until you can consistently win.

Biodiversity, Current Events, and (ouch!) Natural Selection

Biodiversity Research Project - from last week - If you didn't do this yet, compete it now, and be ready to share on Thursday. (for instructions, look at last blog)

Other than that, here is a 10 minute video you might find fascinating; it is about wooly mammoths, and the possibility of un-extincting them by reconstructing their DNA.  How cool would that be!  (?)

For an explanation of Natural Selection,  an 8-minute video by Stated Clearly.  I appreciate that the narrator makes a distinction between "descent with modification" and "common descent"--something I will go over  next class--and the difference between facts  and conclusions. If  you or your parents are concerned about this topic, I understand people have strong feelings about this, and I respect that. This subject requires much thought and discernment.

If you would rather skip the video, do another short report like the last (see Thursday's blog)

 

New Subject: Biodiversity, Meaning LOTS & LOTS of different kinds of animals!

What did I say an ADAPTATION was? --an inherited trait which enables an organism to "fit" into its environment.  It could be camouflage (spell that!) or long legs or sneezing salt, or something much weirder.  Here is an animal that is so crazy I cannot even imagine what all those features are for--the mantis shrimp--Why the Mantis Shrimp Is My New Favorite Animal       


Anyway, here's the real homework:

1.Read the handout from class (one page) 

2. A short research paper: Choose a small animal, like an ant, a frog, a barnacle, a beetle, etc. Research it on the Internet.  These are the questions you should answer:

1. How many different species of [ants,beetles,frogs...] are there in the world?  (Just Google the question, How many species of ant are there in the world?)

2. And where are they found? What types of habitat?

3. Find pictures of 5 of the species.  Copy and paste them onto a Word document.  (Ask your older brother or sister to help.  Or your mom...)

4. Find examples of adaptations that those species have which enable them to fit or survive in their own environment.  For example, of the 10,000 different species of ants, one kind of ant, called a citronella ant is brilliant yellow and emits a strong lemony odor which is expelled from a gland in its head to warn nestmates and drive off enemies.  They are nearly blind and live underground.

Citronella ant

 

Digging Deeper with DNA

How do pirates make proteins?  With Aaaarrrh-NA.  (just a little Harmon family humor.) Get it???

OK< Class was fun; good work on your models. On to the homework: more videos:)

Brainpop.com >>>  pcshome / ilearnathome
Just movie, quiz and FYI

http://www.brainpop.com/health/bodysystems/immunesystem/

http://www.brainpop.com/health/diseasesinjuriesandconditions/vaccines/

=====================
But wait, there's more!

Self-Assembly: The power of organizing the unorganized


And....More Pirates...
RNAi Discovered

RNAi Therapy

 

Viruses: Little Bits of Pirate DNA

Next class we will be making models of viruses, which are little bits of rogue DNA or RNA surrounded by a protein coat which wiggle their way into cells.  They hijack the machinery of the cells to make copies of themselves, then they blow up the cells and escape to infect more cells, and so on and so on.  So for background, here is some Brain.pop to clue you in:


First, a review of RNA:
login:  pcshome   ilearnathome
http://www.brainpop.com/science/cellularlifeandgenetics/rna/
Print/copy out activity page (vocabulary) and either write down what the words mean or draw it.  Watch the movie, take the quiz and read FYI.

Then, the Virus:
http://www.brainpop.com/health/diseasesinjuriesandconditions/viruses/  Print/copy out activity page (vocabulary) .  Watch the movie, take the quiz and read FYI.

A few shorties: 

 

 

By the way, I just wanted to say how much I respect the level of attentiveness and seriousness this class generally gives to their studies--I loved the reports I got to watch.  HOWEVER, PLEASE DISCOVER THE PENCIL POUCH, AND NEVER AGAIN TELL ME YOU DON'T HAVE A PENCIL!  (pens are cool too.)

You Knit Me Together...

  Now that we have extracted DNA from strawberries, split peas and broccoli, can you agree with me that DNA is amazing and beautiful?  How about just amazing??  Every living thing has DNA, which stores the information to copy itself, to make new proteins and to direct the activities of the cell.

On Monday we will finish our unit on DNA by watching some videos that will put it all together for us--DNA in ACTION!  And we'll take a look at how our technology has been revolutionized by the discovery of Watson & Crick  back in 1953, when they walked into a bar and said, "We've found the secret of life!"

Homework is to complete the Chapter 4 review (not section review, but the questions at the end of the chapter.) 

By the way, has anyone seen my copy of the textbook? It  has "teacher" written on the sides.

DNA-->mRNA--> [ribosomes-->amino acids] -->PROTEIN! -->TRAIT!

Today's Lesson: We learned about how DNA does the job. DNA, the double helix that codes for all the genetic information of  life, does more than make copies of itself. It copies pieces of itself to mRNA, which then travels out of the nucleus and inserts itself into a ribosome.  The ribosome reads the code and then assembles the protein.  The protein is a string of amino acids that curls up into a useful shape.  The protein does its job, and that results in an inherited trait, like eye color, or even hitchhiker's thumb!
Finish up the bugs from class and paste them in your lab books.  If you need a new copy of the handouts, see here: https://docs.google.com/file/d/0B07s3-bcUr7ta0pOVkl1eGR2SXc/edit

ALSO: READ CHAPTER 4, SECTION 2 AND ANSWER THE REVIEW QUESTIONS. 

Mother's Day coming up. Have you thanked her for your DNA?/

DNA Replication

Homework for Monday:  Read textbook Chapter 4, section 1, What Is DNA? and answer the chapter review questions.

Also, a brainpop lesson:
brainpop.com DNA
movie, quiz, FYI
[ pcshome / ilearnathome ]

ThANks!

The Nuts and Bolt of DNA

Today's homework is THINKING about yesterday's class--in your lab books, DRAW the model as you remember it, and write down the significant ideas that we discussed in class, as much as you can remember.  Then PONDER the question: How does the shape of the DNA contribute to what it does? (And what actually does it do?)  How might it contain information? How does it copy itself?  Write down your ideas.

Two videos: First, Watson & Crick: Unraveling the Mystery of DNA (6 minutes - the history of the discovery) -
Second, Jim Watson Explains DNA Base Pairing  

The Test Is on Thursday...

Chapter 3 test is on Thursday, so study!
It would be helpful to read over the blogs since March 26th, when we started this chapter by dissecting flowers.  Pay attention to what I write on the blog--it's there because I think it is important!  And always, always, always, try to understand the Main Ideas.  It's so easy when you are studying for a test to try to remember vocabulary and facts, but these you will forget unless you understand why you are learning them in the first place. "The reason for a flower is a...???"  The reason for mitosis... the reason for meiosis...  These are the Big Ideas.


 

• -Explain Mendel's experiment.
• -Practice some Punnett squares [here's a worksheet] and 
• -brush up on vocabulary http://quizlet.com/20029458/chapter-3-science-vocab-flash-cards/ 
• - Memorize the parts/functions of a flower.

Y are you a boy?

To review yesterday's lesson, here's a video by Mr. Anderson, a really great high school teacher (this gives you bragging rights, "I'm doing high school level science...") Younger students may skip, if they wish: 10 minutes

Subject of the homework:
How chromosomes determine gender (the Y makes the guy)
Why men get some genetic disorders more often
What is a pedigree? (no, it's not a foot massage)

Read the rest of ch.3, section 3: pages 73-74 and answer the review questions on page 75.

OR:
Brainpop.com (pcshome/ilearnathome)
Gender Determination movie+quiz+vocabulary page
Twins movie+quiz+vocabulary page

Chapter 3 Test NEXT THURSDAY! -will include vocabulary, Punnett squares and the main ideas listed on the Summary Page.

The Dance of the Chromosomes

Good to be back!
Big day for most of us yesterday, and so it's taking me a little bit to get the homework up, but if you want to get started, read in your textbook from Ch.3, section 3 - Meiosis (my-O-sis), just pages 68-72 (not the whole chapter.)

Also, hopefully you have not lost your CD, or should I say, See-D! This is to observe over the next week or two.  Remember to water carefully.  Please take notes/pictures/diagrams of the progress your seed is making. 

We have already learned, so very thoroughly, about mitosis, which is when the cell divides, forming an exact copy of itself with an identical set of DNA. Mitosis happens to make new cells to replace old ones, and for growth,  so those new cells  need to be just like the old ones. The question may have  arisen, how then do we get cells to start a new person, who is not exactly like the parent, who is an original creation?  These cells must be different--they need to be halved, with only one of each type of chromosome from each parent, so that when they combine the offspring will have the right number, and the right kind, of chromosomes.  This is MEIOSIS. And so the next lesson is about the chromosomal dance which creates these amazing cells which create  a one-of-a-kind person who is loved by God.

The two vocabulary words you need to know are... HOMOLOGOUS CHROMOSOMES
MEIOSIS

The Big Idea you need to grasp is the purpose of meiosis, which is variety and uniqueness.


And here are three videos:

1, 2, 3...

Here's some vocabulary you need to know:
Copy this to your lab book:
gene - a section of DNA which codes for a particular inherited trait (makes a particular protein which leads to a particular trait)
allele - a "flavor" of a gene
dominant - an allele which will express itself (we use a capital letter)  BOLD
recessive - an allele which will take a back seat if a dominant allele is present (use a lower case letter)  SHY
homozygous- both alleles are the same (BB or bb)
heterozygous - the alleles are different (Bb)
genotype - the genetic makeup
phenotype - the observable traits or appearance

1.Now watch the video:

2.Now do the Punnett Square Worksheet Print out both pages Punnett Square Worksheet

3.Read through Chapter 3, section 2 - Traits and Inheritance

This should keep you busy on your vacation!  But here's a hint: if you want to do your homework speedily, learn the vocabulary first!  It might be obvious, but it bears repeating: When you know what the words mean, you understand the paragraphs so much better! 

Enjoy your week.

Heredity...

This week's homework will be to review Chapter 3, section 1, this time answering all the review questions and doing the math.  (Yea, math!)

1. Know the vocabulary -- any word written in bold type or italicized.  Heredity, Dominant Trait, Recessive Trait, self-pollinating, true breeding, cross-pollinating, characteristic, trait, first generation, ratio.

2. School to Home activity, page 57. Describing Traits

3. Describe step-by-step Mendel's experiments.

4. Math Practice, page 60.  Also fill out the 4th column in Table 1: Mendel's Results  (find the ratios)

5. Answer section review questions 1-7

0

For reference the video we watched in class is here: Mendel's Peas: Experiments that Changed the World

Good Friday...

It's Good Friday today, and not just because there's no science homework.

I hope you get some time to reflect on the goodness of God and his amazing love for each of us, and his determination to face unspeakable suffering for the sake of bringing salvation and reconciliation to the world.  "Behold, what manner of love the Father has given unto us, that we should be called the children of God!" 

...and a joyful Easter to you as well.

Stop and smell the...

Flowers are an important part of many plants. Plants use flowers to make other plants – to reproduce. Flowers have special parts, called stamens and pistils. When pollen from the stamen finds its way down through the pistil, the flower is pollinated, and seeds start to grow. The seeds eventually find their way to the ground, the seeds sprout, and more plants are born.

Plants have all different styles of flowers. Some flowers have patterns on them that guide bees and other insects to the pollen. Wheat flowers are long and stringy, so when the wind blows, pollen can float easily from stamen to pistil. Some flowers even smell like rotting meat to attract flies. The flies land, pick up pollen on their legs, and dust some of it onto the flowers’ pistils. Although flowers have different shapes, colors, and smells, all flowers make seeds to keep the plant population growing.

Every flower consists of a set of adaptations that help to ensure successful reproduction. For example, flowers often have bright colors, attractive shapes, and pleasing aromas. These traits help them attract insects and other animals that
will carry pollen grains from flower to flower. Pollination also occurs by means other than animals carrying the pollen. For some flowering plants, the wind plays an important role in transferring pollen from plant to plant.

The seed-bearing plants that produce flowers are called angiosperms. The flower produces the seeds, each of which contains a new plant embryo. The parts of the flower are usually found in four whorls, or rings. Petals are one of the four whorls. They attract pollinators. Sepals lie outside the petals. They protect the bud.

The reproductive organs, the stamens and pistils, make up the third and fourth whorls and lie inside the petals. A stamen is a male reproductive part. It consists of an anther that is held up by a filament. The anther produces pollen grains. A pistil is a female reproductive part. Its top is called the stigma. It is sticky to ensure that when pollen grains land on it, they stick to it. The middle supporting structure is the style, and the large base is the ovary, where the eggs are produced.
1. Bill Nye - Flowers! video
23 minutes - 23 points!

2.  Go outside and find 7 flowers (different kinds!) -- locate the stamen and the pistil on each flower. 7 points.

3.  Read Chapter 3, section 1 - about Gregor Mendel and his famous flying peas.    20 points.

50 points possible!  

[Do you crave more science videos? Here's "The Biggest Flower in the World": https://www.youtube.com/watch?v=FHaWu2rcP94&list=PL47D0521D98A9EF1D&index=8]

Worksheet & Review

Homework: Using the handout of onion root tip cells under the microscope, cut  the paper into individual cells and sort them into IPMAT [ Interphase, Prophase, etc...] Don't write on the cells, and skip the cells that are really too blurry to tell! Glue them into a circle --around the edges of the circle, like a clock face, in the order of the cell cycle.  This will give us an idea of how much time this plant spends in each stage. Make it neatly done, label each stage, use good paper, and if you do not understand the directions, CALL me!  Do it right or do it over!

 ALSO - READ CAREFULLY!
Count up how many cells are in each stage, and make a table with 3 columns, like this:

	Number  of cells	% time in this stage
Interphase
Prophase
Metaphase
Anaphase
Telophase

 + Cytokinesis

To find the percentage of time in each stage, divide the "Number of cells" by the total number of cells on the page, and multiply by 100.

Add a Title at the top of the page, and a sentence or two of Summary at the bottom.

When you are done, check to see if you followed the directions completely.
 [If your copy of the handout gets messed up, go here: mitosis onion cells image.]

For reference: here is a website that has good pictures and descriptions.  http://micro.magnet.fsu.edu/micro/gallery/mitosis/mitosis.html

ALSO< Please turn in your chapter 3 review question & answers on Monday. [note to moms of the younger kids: Feel free to modify the lesson according to your own judgement and time constraints.]

Multicellular organisms constantly need to make more cells!

• Each minute your body needs to make ...oh...about 300 MILLION NEW CELLS! A cell spends most of its life working and growing, breaking down sugars, synthesizing proteins, enzymes, and other macromolecules, but cells inevitably wear out, break down and suffer injuries.
• In addition, as organisms grow and change, they need new cells to make more skin tissue, bone tissue, muscle tissue. These new cells can only come from one place: OTHER CELLS - through the process of cell division, or mitosis.
• For multicellular organisms (like us) cell division allows an organism to grow and develop from a single cell to trillions of cells, and also  to repair and replace cells worn out and used up by everyday life

On Thursday we will finish off our Mitosis unit by looking at photographs of real cells and trying to figure out which stage the cell is in.  By looking at the pictures above, you can see the difference between a diagram and the real thing.

HOMEWORK: Review chapter two - re-read sections 1-3 and answer the end of chapter review questions.  This chapter has covered the cell membrane and how materials pass through it, photosynthesis and respiration, and the cell cycle- how a cell duplicates itself.

My Toes Itch

Review: When your body needs new cells, it generates them by MITOSIS!  which is basically sorting the DNA/chromosomes into two sets and then dividing them up so that now there are two cells instead of one.  The new cell contains an IDENTICAL copy of chromosomes.  Each cell in your body, although there are many different kinds, has your own unique DNA -- it is like a genetic fingerprint -- and unless you are an identical twin, no one else has DNA like you do.  That makes you special.

CELLS ALIVE! mitosis Interactive [click to go to site]for fast, click "play" and then slow it down by clicking "step" -- Repeat many times until you've truly understood.

The Cell Cycle has 3 major stages:  Interphase, MITOSIS! and Cytokinesis, and Mitosis has 4 steps.
Here is a way to remember the steps of MITOSIS!
-> Paul Met Anna Twice.--PMAT
Prophase >Metaphase >Anaphase >Telophase

HOMEWORK:  Finish the MITOSIS! flip book, using your textbook or this page, if you wish.  If you need a new copy, go here: MITOSIS! flip book template. 
On the blank pages of the flipbook, write what is happening on that page. -- does this make sense to you?  You should be able to flip the book to see the action, and also to read it like a book with the words on the left hand page and the illustration on the right hand page. Your textbook will help.  If you are not sure what I mean, call me.

And here are some fun videos to watch, made by students: